The present invention regards an instrument for obtaining a reference line to realize, relative to this line, working points, said working points being preferably situated on a working surface.
Presently, different instruments exist which use the rotation of a laser ray to project a laser ray on a surface. The single illuminous point on the surface is the measuring point.
In EP-A-0 617 258 a portable goniometer of the two pivoting arms type is disclosed. The two arms of this known goniometer are hingedly connected to each other. The first arm has to be freely positioned on a reference surface and the second arm can be oriented in view of the first arm in one plane and between an angle of 0xc2x0 and 360xc2x0. The second arm is provided with a laser ray emitting means permitting the projection of a laser ray in a parallel direction relative to the axis of the second arm. The laser ray reaches points which are not within easy reach for the user. Furthermore, also the angle defined between the laser ray and the reference surface can be measured by this known goniometer.
The instrument hereinafter illustrated is based on a different concept which does not use a ray of light projected on a wall in order to define a single illuminated point of measurement but uses the laser ray to obtain an entire reference line for a plurality of working points.
In the present case the laser ray instrument is fixed, preferably as close as possible to the wall, with a particular fixing system which enables a regulation in order to obtain a real ray of light as a reference line. By the presently shown preferred embodiment of the instrument, it is also possible to cut down sensibly on prices which derive from complicated pivoting systems of the prior art and as it is mounted directly on the reference surface also the tripod support costs are eliminated.
A system is provided which enables to resolve problems which all installers encounter when they have to mount in an aligned way any type of apparatus or structure.
The dependent claims disclose particular and advantageous embodiments of the present invention.
To explain the use of the present system, it is described the practical use of the instrument which hereinafter will be referred to as xe2x80x9claser linexe2x80x9d.